Features

By Charvy Narain

Much has changed since the beginning of the year, when University of Oxford researchers first started coming together to fight the novel coronavirus outbreak. But what has remained consistent is that the University of Oxford remains at the forefront of global efforts to combat the SARS-CoV-2 virus and mitigate its many effects: medical students have been stepping up, researchers with clinical skills are returning to front-line clinical roles, and others are offering up equipment and materials, as well as their laboratory skills to help the NHS respond to the crisis.

The University is also working directly with Oxford University Hospitals NHS Foundation Trust to reduce clinical research activity, and instead prioritising research on COVID-19.

Immunity as the key

One such researcher is Professor Tao Dong, a Professor of Immunology at the University, as well as the Oxford Director of the Chinese Academy of Medical Sciences Oxford Institute (COI). The Institute, a collaboration between the University of Oxford and the Chinese Academy of Medical Sciences, has turned out to be particularly well-placed to respond to the coronavirus crisis: its main aim is to deliver innovative ways of managing cancer as well as infectious diseases, and it has close links to clinicians as well as researchers in China.

Professor Dong says: ‘We started prioritising research on COVID-19 back in January 2020. In March, the COI has already provided funding to seven separate research projects unpicking the immunobiology of the SARS-CoV-2 virus, helping Oxford-affiliated researchers to get research started at record speed.’

Professor Dong’s own research group is currently testing samples taken from COVID-19 positive patients in hospital, taken at different time points in their illness. She says: ‘Some people with a COVID-19 infection are able to fight it off successfully, while others get really ill. We are analysing immune markers in patients to see if we can identify markers that predict how a patient is going to respond, and also to identify targets for drugs to make things better.’

Professor Dong does think that understanding the immune response to COVID-19 is going to be key to defeating it. She says: The immune response to this novel coronavirus is quite unusual. Some of the immune responses it appears to be triggering may actually be making things worse, and if we can predict who is going to respond this way, or even better, find ways to change it, we might be able to help patients.’

Vaccine

The immune system is also the focus of the Oxford Vaccine Group and the Jenner Institute, who are veterans when it comes to combating epidemics: in 2014, the Oxford team helped develop a vaccine for the Ebola epidemic in West Africa.  The team are about to start trials in healthy young volunteers in the Thames Valley region, to test the new ChAdOx1 nCoV-19 vaccine.

The new vaccine is already in production but not ready yet. Dr Sandy Douglas, who is leading on the vaccine manufacturing scale-up project, says: ‘The scale of this epidemic poses a huge challenge for vaccine manufacturing. We need to follow rigorous safety standards and that takes time. By starting work on large-scale manufacturing immediately, we hope to accelerate the availability of a high quality, safe vaccine.’

Technology to the rescue

Large-scale usage would also be the key to the success of a mobile contact tracing app, developed by researchers at the Big Data Institute, Nuffield Department of Medicine, that could potentially help slow COVID-19 infection rates, and support countries to emerge from lockdowns safely. But civil liberty issues and ethics were also central to this proposal: researchers from the Wellcome Centre for Ethics and Humanities at Oxford University co-authored this study, and point out that both ethical oversight and public and user engagement would be essential to the app’s potential success.

The idea of an app is one of many emerging at break-neck speed as researchers focus their combined efforts to combat COVID-19.

Looking to the future

Some researchers are looking at what happens to COVID-19 patients over the longer term: Dr Betty Raman says: ‘We know from the previous SARS epidemic that coronavirus infections can have long-term effects on lung function, exercise capacity and quality of life. Tracking the long term effects of SARS-COV-2 may therefore be important and could highlight the need for ongoing medical surveillance and follow-up.’

Recent studies suggest that COVID-19 can affect other organs besides the lungs. So together with Professor Stefan Neubauer, Dr Raman is leading the C-MORE study, which assesses the effects of COVID-19 on multiple vital organs including the lungs, heart, brain, liver and kidneys (as assessed by magnetic resonance imaging) for up to twelve months. The study will also explore the impact of COVID-19 on functional capacity and quality of life for people who are affected by the illness. 

Professor Neubauer said: ‘This research will be important to understand the long-term impact of SARS-COV-2 infection on a holistic level. The results will be important to assess the long-term consequences for healthcare resource planning and to guide development of new therapies.’

These researchers are also collaborating with others at Oxford, including Professors Clare McKay and Peter Jezzard at the Wellcome Centre for Integrative Neuroscience, to assess the impact of SAR-COV-2 on neurological and mental health, along with infectious diseases experts (such as Professor Brian Angus) and others. 

Mental health

Researchers at the Departments of Experimental Psychology and Psychiatry are looking at the longer term, and have launched a study to track young people’s and children’s mental health through the COVID-19 crisis. The study came together in record time. Dr Polly Waite, who is co-leading the study, said: ‘Schools closed in the UK on Friday 20^th March, we had the idea for the study on Sunday 22^nd  March, and we had the survey out on following Monday, on 30^th March.’

Dr Waite is a working clinical psychologist, and her research is usually focussed on managing anxiety in young people known to have anxiety disorders. “But the closure of schools and nearly all families having to stay at home is quite unprecedented, and we know that many young people already struggle with general anxiety, depression and OCD,” says Dr Waite. So the survey aims to identify what factors might protect children and young people from worsening mental health, what particular stress points there might be, and how this might vary according to factors specific to the child and family.

Professor Cathy Cresswell, the study’s other co-leader, says, “We hope to have more than 10,000 parents and carers across the UK complete the new online survey. Their responses will help us really understand how families are coping and what support could make all the difference to children, young people and their families at this time.”

The research team hope to track families over the next twelve months, including when children might return to school. “That may bring a whole new set of challenges for a family, but children are generally quite resilient,” says Dr Waite. “But again, what we want to do is try and track why and how some children have an easier time readjusting compared to others.”

Parents resource

In collaboration with the World Health Organization and UNICEF, the University of Oxford has also launched a parenting resource for self-isolating families.

One Oxford

During this challenging time, some of the world’s brightest minds are coming together, working in unprecedented ways to deliver world class research with global benefits and to make an impact on the frontline of this crisis. Oxford is made of its people, and these achievements are a result of contributions on all levels as we continue to face this global challenge, together.

Find out more about the University of Oxford’s coronavirus research.

Professor Louise Richardson, Vice-Chancellor of the University of Oxford, explores the international response to Covid-19 and the role of universities, who are working with colleagues across the globe to understand the disease and protect our communities.

(An edited version of this article appeared in Foreign Affairs on 9 April 2020)

One of the very many disheartening aspects of the Covid-19 pandemic is the near absence of international institutions in fashioning a response to this global crisis. The G7 could not agree a statement and the G 20 could only agree that the problem was both global and serious. Disease, like other grave threats to the world today, most notably climate change, does not respect national borders and yet the response has tended to be a nationalist one. It is precisely at times like this that we need strong international institutions who will share information, insist on reliable information - and have the courage to call out those not providing accurate information – and who will ensure that the poorest countries and their populations are not forgotten in the rush for an effective response. The WHO has been the only international institution in evidence throughout the crisis.

It is striking that while the US, the UK, and other countries are committing eye-watering sums to tackling the pandemic and mitigating the impact on their population and their economy, the amount of funding committed to the developing world is derisory. Countries in Africa are not yet indicating large numbers of cases but that is only because they do not have the means to test and we know their health care systems are seriously under resourced at the best of times.

That this pandemic occurred at all, of course, reflects a failure of international institutions and national governments too. We have had warnings. The SARS epidemic of 2002-04 was believed to have begun in an Asian wet market. The current coronavirus is believed to have begun in a wet market in Wuhan, and reports are that as China returns to normal, wet markets are again emerging in the poorest districts of some Chinese cities. The Ebola crisis should have served as a warning too but that involved people dying far away from the wealthy streets of the west and the lessons were ignored.

There was no shortage of people pointing to our vulnerability to a pandemic, and they were not all obscure academics, just see Bill Gates’ TED talk of 2015 in which he contrasted the vast sums spent on nuclear deterrence to the paltry sums spend on pandemic preparedness. Governments have preferred to see security in military terms, epaulettes never stethoscopes. Production of vital pharmaceuticals were outsourced to the cheapest providers, generally China and India, all in the name of private profit and public economy.

We seem to have come full circle. Globalisation, which brought enormous wealth to many parts of the world, led to gross inequalities in the distribution of it benefits. Those who lost out took their revenge at the ballot box and elected leaders the world over on a populist tide. These leaders, in turn, showed only distain for the constraints imposed by international institutions and unilateralism reigned. Now we all face a global crisis which requires international co-operation, but the mechanisms for delivering it have been weakened.

Far below the haute politique of international relations there are global institutions in the trenches that are working to find a vaccine, develop effective therapeutics and use technology to design treatments and expedite mass production. They are working together with colleagues from around the world, including the global south. They are, of course, universities.

I can speak only to the work of my own university, The University of Oxford. But there are a great many other universities around the world in which international teams of talented and committed researchers are working around the clock to find a cure for, and mitigate the impact of, Covid 19.

While the medieval streets of Oxford are deserted some of our labs are buzzing. We have an estimated 500 researchers, assisted by an equal number of technicians and support staff, who are engaged in Coronavirus related research. We also have large teams around the world, in Thailand, Vietnam and Kenya who are working with local collaborators, as they have done for years, seeking to build local capacity and to understand and to counter respiratory and other diseases.

The University of Oxford has been around so long we don’t quite know how long, but between eight and nine hundred years. We have lasted as long as we have because of the enduring value of what we do: push at the frontiers of knowledge, educate the next generation, and contribute to the world around us. The growth of the University accelerated after 1169 when Henry II banned English scholars from travelling to the University of Paris. Efforts to constrain the free flow of ideas have never worked and Universities have thrived precisely because of our ability to recruit scholars from anywhere and everywhere who want to engage with one another. Just two months ago my biggest challenge was responding to the constraints Brexit might pose on our ability to recruit globally. Today that challenge pales into insignificance in the face of the enormous financial and operational challenges posed by this pandemic.

While we are responding to the challenges presented, we take enormous pride in the work of our academics, medics and researchers. These scholars, from all over the world, are not driven by individualistic competition for plaudits, profits or political advantage but rather by the age old mission of contributing to the world around us.

Here in Oxford a team at the Jenner Institute led by Professor Sarah Gilbert, that had previously worked on a vaccine for MERS, has identified a non-replicating viral vector vaccine candidate: ChAdOx1 nCoV. GMP manufacturing at the Clinical Biomanufacturing Facility in Oxford is in progress. Recruitment for human participants has begun with plans for first-in-man testing by April 22nd. This is an international effort with plans for large-scale production in Italy, India and China. Simultaneously the vaccine is being tested for protections against disease and the absence of any adverse effects in animal models in Rocky Mountain Labs in the US and Porton Down in the UK. We believe this to be the only vaccine candidate aiming for efficacy in humans by late June.

In addition to working on a vaccine our researchers are developing and repurposing drugs, predicting future outbreaks, informing public health, developing diagnostic tools and understanding behaviours and the resulting social impact.

Professor Peter Horby, who led the University’s work in response to SARS when he was Director of the Oxford University Clinical Research Unit in Hanoi, Vietnam and later led our response to Ebola, has been contributing to the response in Wuhan since early January, including the first randomised controlled trials of anti-viral drugs. He and other colleagues have been collaborating with the Chinese Academy of Medical Sciences and the China Centre for Disease Control throughout the crisis. In the UK he and other Oxford researchers have launched a national clinical trial to test the effectiveness of the HIV drug lopinavir-ritonavir and the steroid dexamethasone in the treatment of Covid 19 patients. Meanwhile Professor Guy Thwaites is conducting a clinical trial of chloroquine for the treatment of Covis-19 in Vietnam, in close collaboration with the Vietnam Ministry of Health.

Medics in our overseas programmes have been working on respiratory diseases for a long time. Our team in Thailand, led by Professor Nick Day and working with colleagues in the Mahidol Oxford Tropical Medicine Research Unit which, like our other oversees programmes, is funded by the Wellcome Trust, is conducting large scale multinational clinical trials. They are currently conducting a trial of chloroquine/hydroxchloroquine for the prevention of Covid-19 in healthcare workers, with planned sites in Thailand, Vietnam, Laos, Italy and the UK. They have also simulated and advised on chloroquine dosing for the WHO-led multi-centre study. The environment for scientific studies on these drugs has been difficult ever since President Trump promoted them as a cure for Covid-19. The Indian government has now recommended hydroxychloroquine as prophylaxis for health workers without evidence of its benefit, so a randomised trial cannot be conducted. Publicity around the benefits of the drug has also led to fatalities as individuals treat themselves and accidentally overdose. In addition to clinical trials our teams in Thailand are modelling the out-break of Covid-19 in Asia and working on optimising critical care in low resource settings.

Oxford academics have been based at the KEMRI Wellcome Research Programme - where there are 850 employees - for over 25 years. They work across three main hubs in Kenya and Uganda; Nairobi, Kilifi and Mbale with further international reach through collaborating sites. Led by Professor Philip Bejon, KEMRI-Wellcome site has been at the forefront of developing vaccines for Malaria. Currently they are one of three sites in the country testing for Covid 19. They have worked on a long list of vaccines and conducted phase 1 Ebola trials as well as early stage trials of Rift Valley Fever and Yellow fever.

Their modelling group has spent almost 15 years working on respiratory viruses in Kenya. As such they understand the pattern of contacts. So that if a healthy male in a rural Kenyan homestead gets a disease they have the data to know how many people he will have been in contact with. In the words of Professor Bejon: “You can’t decide to start doing these things when the crisis strikes, you have to be there already.” As a result of a programme of capacity building over many years most of the programmes are led by impressive Kenyan scientists. The KEMRI-Wellcome team are keen to work with colleagues in the Jenner Institute in Oxford so that they can test the vaccine arguing that they do not want all the early testing done in Europe, which would inevitably mean a delay in getting the vaccine to Africa.

There are a great many more examples of Oxford’s medical researchers collaborating with colleagues around the world to help to fashion a more effective response to this pandemic. The contributions are not only made by medics. Our engineers too are developing ventilators, testing kits and tracing apps, while social scientists are modelling societal reactions and adaptations. In short, it is the bringing together of people from different nationalities, different perspectives, different disciplines with a shared commitment to translate the academic research of the university for the betterment of society that is leading the way in the global response to Covid 19.

In the absence of effective international institutions, universities are stepping into the breach in the search for a cure for this disease, but only international institutions will be able to ensure that the impact of this pandemic does not exacerbate the inequities that already exist in global society. In the past international institutions were forged after major military conflict or major financial disruption in an effort to ensure that they would not recur. We know that this will not be the last pandemic. We need effective international institutions, supported by governments with the wealth to do so, to ensure that the next time we are prepared.

With churches and places of worship closed, this would seem a very unholy Holy Week. Palm Sunday got it off to a modest start, with a video of a lonely-looking Pope Francis holding a massive palm, to remind us that this is the most important week of the Christian year. Processions of hooded penitents are absent from Coronavirus-hit Spanish squares and, around the world, even Easter Sunday will see pews empty and peals un-rung. Meanwhile, in the Jewish world, Passover meals, which take place this evening [Wednesday 8 April] will not be the usual large family gatherings. And all because of Covid-19.

Oxford Professor Diarmaid MacCulloch dismisses the Papal Interdict of 1208 as utterly different [from the Covid-19 closures]: a ‘political’ move by the papacy, not intended to protect churchgoers

A vocal group of angry churchgoers has maintained that, not since King John have the churches of England been shut. But Oxford Professor Diarmaid MacCulloch, professor of the History of the Church, dismisses the Papal Interdict of 1208 as utterly different: a ‘political’ move by the papacy, not intended to protect churchgoers.  Nevertheless, more than a few people have asked where God is in this crisis and why churches are closed during the time of Covid-19.

In the United States, some churches have remained defiantly open, while others have followed medical advice and closed their doors. In the UK, it has become a controversial matter in church-going circles, although not in general and one letter to the Daily Telegraph pointed out that pubs were closed, so why not churches – likening religious life to a form of leisure activity.

According to Professor MacCulloch, social attitudes about church going changed in the late 1950s, when it ceased to be seen as a likely criterion for middle-class respectability: ‘There was a remarkable move away in the 1960s...followed by the collapse of the Sunday School movement...Church attendance was no longer a component of respectability.’

Yet the author of Reformation - Europe's House Divided 1490-1700 says, the current debate over church closures has a lot to do with Protestantism – which thrives on large-scale, noisy worship and does not have any history of silent spirituality. This, he says, was dispensed with, along with the monasteries at the time of the Reformation. Professor MacCulloch maintains: ‘Historically, Protestants do not have many spiritual resources to deal with spiritual isolation...sixteenth century Protestant churches were all about crowds getting together to hear sermons and to sing, especially metrical psalms.’

It is noticeable, he says, that in the US the divide on staying open has been very much along political party lines, with large Protestant mega-churches trying to remain busy: ‘There is a cultural chasm...mainstream churches such as the Episcopalians have closed, as the right thing to do.’

Once the monasteries were closed in the sixteenth century, Protestant churches lost spiritual resources associated with them

Professor MacCulloch, who also wrote Silence – A Christian History, adds: ‘Once the monasteries were closed in the sixteenth century, Protestant churches lost spiritual resources associated with them. The only Protestant Church to include silence in worship was Zwingli’s in Zurich and it wasn’t long before congregations got bored with it.’

He maintains: ‘It’s a long catch-up for the Protestants on silence. In the 20th century they started to realise this and ceased to be averse to monasticism.’

But, he points out, attempts to recreate such spirituality is a bit like trying to reinvent the wheel. 

This Holy Week, though, Covid-19 social distancing means that many churchgoers in the UK and around the world have a chance to experience contemplation and meditation more commonly found in the cloister. 

It’s not every day that the FBI takes a close interest in a senior Oxford academic’s blog. But, then again, a million television programmes suggest maybe it is.  Whatever the case, Professor Bill Dutton’s recent blog about the conferencing platform, Zoom, preceded a lively international debate – and interest from the Feds in his native US.

Ahead of the curve, Professor Dutton, who was a founding director of Oxford’s Internet Institute and is currently a senior fellow, wrote a blog with colleague, Arnau Erola, highlighting the potential problems and issues around video-conferencing: Zoom-bombing the Future of Education.

Since the beginning of the Covid-19 crisis, the highly-accessible provider, Zoom had gone from geek-obscurity to household name and in a matter of days the number of its users increased from 10 to 200 million, as people around the world tried to overcome social distancing to connect with colleagues, friends and students.

But, as Professor Dutton, who is also a fellow of the Global Cyber Security Capacity Centre (GCSCC) of Oxford’s Department of Computer Science, says, problems were not far behind: ‘It took about a week.’

With the increased use of Zoom and other platforms, came issues. In his blog, he wrote: ‘One particular challenge that has risen in prominence is efforts of malicious users to sabotage classrooms and discussions, such as by what has been called Zoom-bombing (Zoombombing). Some have defined it as ‘gate-crashing tactics during public video conference calls’ that often entail the ‘flooding of Zoom calls with disturbing images’.’

And, since the  26 March publication, the topic has hit the headlines in the UK and around the world, as ‘bombers’ have interrupted and disturbed video-conferencing events from Jewish religious services to corporate meetings, often with malicious intent. News stories have appeared, voicing concerns about the security and protection of video-conferencing.  Blame has been levelled against key providers. But, many of the issues are actually related to the users moderating the conference, rather than the software, says Professor Dutton.

He maintains, there are numerous ways in which meetings and events can be safeguarded from malicious intent. He says: ‘There has been exaggerated coverage of the problems. It’s not usually a problem with the software. Many of these issues can be addressed by the moderator.’

It’s the job of the moderator to set up the meeting...Zoom is incredible, it’s brilliant technology

Professor Dutton adds: ‘It’s the job of the moderator to set up the meeting...Zoom is incredible, it’s brilliant technology.’

A main issue is the overnight success with new users, who are unfamiliar with the technology and failing to use the safety and security measures that are available. Professor Dutton maintains: ‘Part of the problem is that Covid-19 moved so many people online so quickly. Teachers and people with no background are using [this technology] because it is so simple. But it made them vulnerable to malicious intent [because they did not take the security measures that were available].’

But, says Professor Dutton, there are ‘all sorts of settings’ that could be used by the moderator [or organiser of the meeting], from using passwords, only accepting participants with known email addresses or invitations and control of visuals and audio. These can prevent unauthorised persons gaining access to private meetings and provide the safe space that organisers and legitimate participants seek. As well as commending guidance and training for novice staff, Professor Dutton made six key recommendations in his blog, aimed at ensuring safety:

• Authentication – limit the connection to specific users;
• Authorisation – restrict the technical facilities of participants, so they can’t disrupt or show offensive material;
• Monitoring – although a laborious process, participants should be reviewed to prevent gate-crashers;
• Moderation – participants’ activities can also be reviewed – particularly useful in an educational context;
• Policies – each institution using such technology needs to have set-down policies of acceptable and unacceptable behaviour;
• Procedures – anyone breaching the rules could lose authorisation or be dealt with using laid-down procedures.

Not long after the blog was published, the FBI launched its own recommendations – which are very similar to those from Professor Dutton’s team. 

Not long after the blog was published, the FBI launched its own recommendations – which are very similar to those from Professor Dutton’s team

‘They pretty much aligned with our recommendations,’ he says, clearly amused.

With so much official and corporate business being conducted online, it is evidently a high-priority for the Bureau, which only yesterday threatened ‘zoom-bombers’ with ’jail time’.

Professor Dutton’s blog, meanwhile, saw particular problems for educators, he wrote: ‘It is clear that zoom-bombing has become an issue for schools and universities, threatening to undermine the vitality of their teaching and relationships with faculty, students, and alumni of their institutions.’

Reflecting on the need for security, he says: ‘It undermines the whole culture of education, which should be open and accommodating.’

The Professor points out that, in usual times, lectures can be open to any student. But these are not usual times and when setting up a class remotely, it will be necessary for the moderator to take steps which they would not otherwise consider. He recognises that this will not come naturally to all. Professor Dutton says: ‘Universities need to provide the resources for IT staff to brief academics and do some hand-holding.’

The University’s preferred video conferencing tool is Microsoft Teams but we have issued guidance to staff members on the usage of Zoom at https://www.infosec.ox.ac.uk/article/guidelines-for-using-zoom

The blog was written by Professor Dutton and Arnau Erola and was based on their discussions with Louise Axon, Mary Bispham, Patricia Esteve-Gonzalez, and Marcel Stolz

Considerable uncertainty surrounds Covid-19 - how long it will take before a vaccine is developed, the death rate amongst cases and even how many cases there have been so far. But there is one thing of which we can be sure: social distancing works, according to a mathematical modelling expert from Oxford University.

Dr Robin Thompson, a junior research fellow in mathematical epidemiology, has crunched the numbers and found social distancing can reduce pass-on rates of Covid-19 substantially. His mathematical modelling, based on measures now in place to reduce person-to-person contact, reveals a scenario in which case numbers could be reduced by almost 90%:

• Without social distancing, one coronavirus sufferer could, in six weeks, have started chains of transmission with 1,093 cases;
• With social distancing, the same sufferer could, in six weeks have started chains of transmission with 127 cases.

Without social distancing, one coronavirus sufferer could, in six weeks, have started chains of transmission with 1,093 cases. With social distancing, the chains of transmission [would involve] 127 cases.

Dr Thompson’s work is based on the reasoning that one individual with Covid-19 will pass it onto three other people over the course of their infection. In a further week, each of the three will have passed it onto another three people. Each week, each person will infect three more people, so that, after six weeks, the initial individual will have started a chain of transmission leading to more than 1,000 cases, says Dr Thompson.

But, the mathematician says, introduce social distancing and the picture is very different. If we are all able to reduce our effective contacts by one third, there is a dramatic difference in the numbers of infections. On this basis, after six weeks, there would be 127 cases in total.

Social distancing, he maintains, removes any question of people wondering whether they or a particular individual has the infection. Dr Thompson says: ‘Social distancing is of clear public health importance. It involves all of us reducing our contacts, irrespective of whether or not we think we are carrying the virus. It means that infected individuals are less likely to transmit the virus, and healthy individuals are less likely to contract it.’

Dr Thompson points out it is particularly relevant to Covid-19: ‘It’s very hard to self-determine whether or not we’re infected. Even if we are carrying the virus, we may have no or very few symptoms. We could therefore be spreading the virus without even knowing it.’

It’s very hard to self-determine whether or not we’re infected. Even if we are carrying the virus, we may have no or very few symptoms. We could therefore be spreading the virus without even knowing it

He says most people are following the social distancing measures and reducing their social contacts. But he says: ‘We all need to go shopping sometimes. However, by following social distancing, we can all make a difference.’

He insists: ‘It’s all of our responsibility to avoid going on a hike where lots of people group together...Social distancing works.’

Dr Thompson also notes that, while social distancing is currently necessary, it is not required for outbreaks of other diseases: ‘For SARS, social distancing measures were not required because infectious individuals displayed clear symptoms. As a result, the outbreak could be controlled by finding and isolating symptomatic cases. That appears not to be the situation for Covid-19, due to the wide spectrum of symptoms.’

The results of social distancing may not be seen immediately, according to Dr Thompson, because of the time lag between transmissions and individuals becoming infected and displaying symptoms. However, as his calculation demonstrates, measures implemented now can be expected to have substantial effects on future case numbers.